I think it's cool that we now know how he awakened his Sharingan. But what I don't understand are some of the readers' reactions. People are saying they hate Kakashi now and whatnot. I don't understand how Rin could be so important to a reader that they would hate Kakashi for killing her.
"The life of an assassin is pain, Jun. You suffer it, you inflict it, you watch it happen, in the hope that you can help it disappear in time." - Ezio